1. Field of the Invention
The invention relates to methods and procedures for building construction and more particularly the invention relates to a method of erecting or forming the footing and first course concrete block which provides the foundation for a building structure.
2. Description of the Prior Art
The customary procedure used to erect the foundation for a building structure includes the procedures of forming a trench in the ground at the location where the building is to be erected. Reinforcing steel, commonly called "rebar" in the industry, is supported in the trench to provide additional strength to the concrete footing. This rebar is required by various building codes in connection with building most, if not all, commercial structures and additionally a very large majority of residential structures employ rebars or reinforcing steel in forming the foundation.
After the reinforcing bar is supported in the trench at the proper level, concrete is poured in the trench to surround the rebar and is allowed to set. This setting normally takes a day to complete and can take longer.
After the concrete footing has set, a first course of concrete block is laid or erected on the set footing. This first course of block will normally require leveling procedures so that subsequent courses of block which are erected upon the first course to form a wall structure will be level. Since the footing concrete has set when the first course of block is laid, the joint between the concrete footing and the block to be laid will be a cold joint, because the block concrete and footing concrete do not set at the same time. Such cold joints are not as desirable or strong as if the concrete in the footing were partially or completely unset when the first course of block is laid up.
One obvious disadvantage of the standard procedure is that it is necessary to wait a day between pouring the concrete footing and laying the first course of block. Further, as already mentioned, a cold joint exists between the cement used to lay up the first course of block and the concrete booting.
Various devices have been proposed for supporting the reinforcing steel (rebar) which is used in most construction projects. U.S. Pat. Nos. 4,085,559 and 4,627,205 show devices used to support rebar in building foundation constructions. Likewise, U.S. Pat. No. 1,729,612 shows a device for supporting a rebar in the construction of a concrete floor. U.S. Pat. No. 3,104,600 illustrates a system of forming the joint in a concrete highway.
U.S. Pat. No. 3,318,059 discloses a system for forming a concrete footing which provides a level top surface to support the first course of block to be laid on the footing. This construction involves the use of a series of grade stakes which are placed in the footing trench prior to pouring the footing concrete. These grade stakes support an elongated plate which is leveled at the time of erection and ultimately becomes a part of the top surface of the footing.
U.S. Pat. No. 2,815,656 discloses a method of forming a wall construction that involves the insertion of a series of U-shaped supporting members in a footing trench which support a series of rebars. A small layer of concrete is poured in the bottom of the footing trench to stabilize the inverted U-shaped members and support the rebars. A corrugated wall member is supported on the inverted U-frame member and additional concrete is poured with a second set of rebars supported by transverse rods extending through the corrugated wall members. Concrete footing is then poured over the previously poured stabilizing portion and a series of vertical tie rods are installed in the wall which serve as a means of positioning the upper edge of the wall. A wooden form is also employed in this system.
From the standpoint of labor savings, which in today's building construction industry is a major building cost factor, it would be desirable to provide a system of erecting building foundations in which the concrete footing and first course of block can be accomplished in a more efficient manner than at present. At least two advantages will be obtained thereby. First, such a procedure will eliminate the necessity of waiting for the concrete footing to set prior to laying up the first course of block. Also, the cold joint between the cement used to bond the first course of block to the footing will be eliminated.
None of the prior art methods disclose a system in which a concrete footing can be erected by constructing the footing and first course of block in one unified procedure. Accordingly, a need has existed in the building construction industry to provide a system for more efficiently and effectively erecting a building foundation.